Ministers approved the emergency funding after a request from the force. Wiltshire Police and Crime Commissioner Angus Macpherson said it was important additional costs "were not of detriment to the residents of Wiltshire". The government said it would also consider a request for £1.9m for the 2018/19 financial year after the investigation had completed.

A statement from the government said it remained "committed to working alongside the local authority and emergency services to help the area meet any further exceptional costs arising from this incident", including "meeting the cost of cleaning up contaminated sites".

Mr Mcpherson said he had made the funding request to government last week following the "unprecedented incident" which meant "significant costs" had been incurred. He said: "Salisbury has been drawn into an international debate and it's important that they are not left shouldering the weight on behalf of the country."

The government said it was also working through requests for additional NHS support. A spokesman said: "The mental health needs of the community may not be clear for some time but we are absolutely committed to ensure effective plans are in place and the community's needs are met now and in the future."

Businesses in Salisbury are being offered compensation from a £1m government fund to help them recover. Traders have been hit by a drop in sales since the Skripals were discovered in The Maltings shopping precinct.